title: Variations in mineral apposition rate of trabecular bone within the beagle skeleton.
abstract: The mineral apposition rate of trabecular bone was determined in several skeletal sites of young adult beagles. Tetracycline derivatives were administered intravenously or orally on 2 separate occasions preceding the day of sacrifice in order to label actively mineralizing bone surfaces. The rate of mineral apposition was calculated by dividing the distance between the 2 tetracycline markers by the time interval between their administration. The lumbar vertebra, proximal humerus, and pelvis, each of which contains red marrow, were found to have a significantly higher (P less than 0.001) rate of mineral apposition in trabecular bone than the skeletal sites containing yellow marrow--the proximal ulna and distal humerus. The mean apposition rate in the former 3 sites was 1.3 +/- 0.3 micrometers/day, while that in the latter 2 was 0.9 +/- 0.2 micrometers/day (uncorrected for plane of sectioning). It is tempting to speculate that this finding may be a consequence of differences in vascularity between red and yellow marrow.
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D001842:Bone and Bones / Q000378:metabolism*; D004285:Dogs / Q000378:metabolism*; D006651:Histocytochemistry; D006811:Humerus / Q000378:metabolism; D007700:Kinetics; D008159:Lumbar Vertebrae / Q000378:metabolism; D008903:Minerals / Q000378:metabolism*; D010384:Pelvic Bones / Q000378:metabolism; D013752:Tetracycline; D014457:Ulna / Q000378:metabolism
chemical_list: D008903:Minerals; D013752:Tetracycline